Process for transferring films

Abstract

A process of transferring a layer of a first material from a first substrate, having defects in a zone close to the surface, onto a host substrate made of a second material includes a step of thinning the first substrate in order to form a first thinned substrate, an ion or atom implantation in the first substrate in order to form an implantation plane therein, delimiting the layer to be transferred, and a transfer of the layer onto the host substrate by fracturing the substrate along the implantation plane.

1. A process for forming a layer on a host substrate, the process comprising:
 a) depositing a monocrystalline layer onto a deposition substrate to form a deposited layer, comprising a superficial portion having a first defect density, the defects comprising crystalline defects or composition homogeneity defects, and a buried portion, having fewer defects than the superficial portion; 
 b) thinning the deposited layer by removing the superficial portion and allowing the buried portion to remain to form a thinned layer, wherein thinning the deposited layer comprises removing at least 500 nm of material from the monocrystalline layer, and wherein the thinned layer has a second defect density that is less than the first defect density; 
 c) implanting ions or atoms in the deposition substrate after thinning the deposited layer to form an implantation zone; 
 d) transferring the thinned layer onto the host substrate; 
 and 
 e) fracturing the deposition substrate along the implantation zone. 
 
     
     
       2. The process according to  claim 1  further comprising, before step c), or before step d), a step of forming at least one intermediate layer. 
     
     
       3. The process according to  claim 2 , wherein forming at least one intermediate layer comprises forming one of more layers of silicon oxide, silicon nitride, or aluminum oxide. 
     
     
       4. The process according to  claim 1 , wherein implanting ions or atoms comprises implanting a dose between 1×10 16  cm −2  and 4×10 17  cm −2 . 
     
     
       5. The process according to  claim 1 , wherein the host substrate comprises one of glass, garnet, sapphire, diamond or ceramic. 
     
     
       6. The process according to  claim 1 , wherein the host substrate further includes a layer to assist with bonding. 
     
     
       7. The process according to  claim 1 , wherein the deposited layer has a thickness greater than 1 μm before step b), and the thinned layer has a thickness below 1 μm after step b). 
     
     
       8. The process according to  claim 1 , wherein depositing a monocrystalline layer comprises epitaxial growth of the layer on the deposition substrate. 
     
     
       9. The process according to  claim 1 , wherein depositing a monocrystalline layer comprises one of liquid phase epitaxy, deposition by laser ablation of a target, cathode sputtering, or ion beam sputtering. 
     
     
       10. The process according to  claim 1 , wherein the material of the deposited layer comprises garnet. 
     
     
       11. The process according to  claim 1 , wherein the material of the deposited layer comprises ferromagnetic garnet doped with bismuth. 
     
     
       12. The process according to  claim 10  or  11 , wherein the deposition substrate comprises GGG, NdGG or SGGG. 
     
     
       13. The process according to  claim 1 , wherein transferring the thinned layer comprises direct or molecular bonding. 
     
     
       14. The process according to  claim 1 , wherein the host substrate includes one or more optical components. 
     
     
       15. The process according to  claim 1 , wherein the host substrate includes one or more waveguides. 
     
     
       16. The process according to  claim 1 , wherein the host substrate comprises a layer of III-V semiconductor material or glass having a variation in ion concentration. 
     
     
       17. A process for forming a layer of garnet on a host substrate, the process comprising:
 a) depositing a monocrystalline layer of garnet onto a deposition substrate to form a deposited layer comprising a superficial portion having a first defect density, the defects comprising crystalline defects or composition homogeneity defects, and a buried portion having fewer defects than the superficial portion; 
 b) thinning the deposited layer, such that a superficial portion of material having a thickness at least 500 nm is removed, and allowing the buried portion to remain, forming a thinned layer, wherein the thinned layer has a second defect density that is less than the first defect density; 
 c) implanting ions or atoms in the deposition substrate after thinning the deposited layer to form an implantation zone; 
 d) transferring the thinned layer onto the host substrate, the host substrate comprising glass, garnet, sapphire, diamond, or ceramic; 
 and 
 e) fracturing the deposition substrate along the implantation zone. 
 
     
     
       18. A process for forming a layer on a host substrate, the process comprising:
 a) depositing a monocrystalline layer onto a deposition substrate to form a deposited layer, comprising a superficial portion having a first defect density, the defects comprising crystalline defects or composition homogeneity defects, and a buried portion, having fewer defects than the superficial portion; 
 b) thinning the deposited layer by removing the superficial portion and allowing the buried portion to remain to form a thinned layer, wherein the thinned layer has a thickness of less than about 1 micron and a second defect density that is less than the first defect density; 
 c) implanting ions or atoms in the deposition substrate after thinning the deposited layer to form an implantation zone; 
 d) transferring the thinned layer onto the host substrate; 
 and 
 e) fracturing the deposition substrate along the implantation zone. 
 
     
     
       19. The process according to  claim 18 , wherein the deposited layer has a thickness greater than 1 μm before step b), and the thinned layer has a thickness below 1 μm after step b). 
     
     
       20. The process according to  claim 18 , wherein transferring the thinned layer comprises direct or molecular bonding. 
     
     
       21. The process according to  claim 18 , wherein thinning the deposited layer comprises removing at least 500 nm of material from the monocrystalline layer.